Gimbal system

ABSTRACT

A gimbal system. The gimbal system may include space-saving features configured to accommodate one or more payload components, thus increasing the payload capacity of the gimbal ball without necessarily increasing the outer dimensions of the gimbal ball. Alternatively, or in addition, the gimbal system may include a motor configured to move at least one gimbal relative to another gimbal about a first axis, with the motor peripherally mounted distal the axis.

CROSS-REFERENCE TO RELATED APPLICATION

This application incorporates by reference in its entirety for allpurposes U.S. patent application Ser. No. ______, filed Oct. 1, 2004(the same day as the present application), titled “GIMBAL SYSTEM,” andnaming Tim Wescott, Greg Dent, and James Weaver as inventors.

BACKGROUND

Cameras, infrared sensors, compasses, weapons, and other devices can bemounted and used on a variety of supports. For example, moving vehicles,including various aircraft, watercraft, and ground vehicles, can provideversatile supports capable of transporting such devices. Many devicesbenefit from being easily and accurately pointed at a desired target.Gimbal systems can be used alone, or with gyroscopic stabilization,easily and accurately to point such devices without necessarily havingto reorient the supports to which the devices are mounted.

Gimbal balls, as used herein, are any device-mounting mechanisms thatinclude at least two different, typically mutually perpendicular, axesof rotation, thus providing angular movement in at least two directions.A gimbal ball can include one or more constituent gimbals, each of whichcan rotate relative to one or more other constituent gimbals and/or asupported payload. A gimbal ball also can include corresponding motorsfor rotating the various gimbals, control systems for controlling thevarious motors and/or payload components, gyroscopes for stabilizing thepayload, as well as any other components used to aim and/or otherwisecontrol the payload.

SUMMARY

The present teachings disclose a gimbal system, including components andmethods of use thereof. The gimbal system may include space-savingfeatures configured to accommodate one or more payload components, thusincreasing the payload capacity of the gimbal ball without necessarilyincreasing the outer dimensions of the gimbal ball. Alternatively, or inaddition, the gimbal system may include a motor configured to move atleast one gimbal relative to another gimbal about a first axis, with themotor peripherally mounted distal the axis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a gimbal ball mounted to a support.

FIG. 2 is an axonometric view of an exemplary gimbal ball (containing acamera payload) mounted to an exemplary support (i.e., a helicopter).

FIG. 3 shows the various gimbals of an exemplary gimbal ball.

FIGS. 4 and 5 somewhat schematically show two different gimbals that canbe incorporated into the gimbal ball of FIG. 3.

FIGS. 6 and 7 respectively show axonometric views of the gimbals ofFIGS. 4 and 5.

FIG. 8 is a side-view of the gimbal of FIGS. 5 and 7.

FIG. 9 is a schematic view of an exemplary gimbal ball.

FIG. 10 is a front view of motors peripherally mounted in an exemplarygimbal ball.

FIGS. 11 and 12 are side-views of one of the motors of FIG. 10.

DETAILED DESCRIPTION

FIG. 1 schematically shows an exemplary gimbal ball 10 mounted to anexemplary support 12.

A gimbal ball, as used herein, generally comprises any device-mountingmechanism that includes at least two different axes of rotation, thusproviding angular movement in at least two directions. A gimbal ball canbe configured to rotate a payload about any suitable or desired numberof axes, including two axes, three axes, four axes, five axes, six axes,or even more than six axes. In some embodiments, the axes of rotationmay be collinear or coplanar. In some embodiments, at least one axis maybe located in a different plane than another axis. The axes of rotationgenerally are either perpendicular to one another or parallel to oneanother, although this is not required. Nonparallel axes allow a payloadto be aimed two dimensionally, such as up and down as well as side toside. In some embodiments, parallel axes, or substantially parallelaxes, can be used to provide increased precision, with a first level ofrotation about a first axis providing coarser large-magnitudeadjustments and a second level of rotation about a second axis parallelto the first axis providing finer small-magnitude adjustments.

A support, as used herein, generally comprises any mechanism for holdingor bearing a gimbal ball. For example, a gimbal ball can be supported bya moving support, such as a helicopter, airplane, glider, dirigible,balloon, drone, boat, car, truck, motorcycle, missile, rocket, orvirtually any other vehicle, among others. Alternatively, or inaddition, a gimbal ball also can be supported by a stationary support,such as an observation platform or tower, among others. Typically, thesupport is selected to complement the function of the gimbal ball.

A gimbal ball and support may be connected, joined, or otherwiseassociated using any suitable mechanism, with any suitable orientation.For example, a gimbal ball may be bottom-mounted, side-mounted,top-mounted, front-mounted, rear-mounted, externally-mounted,internally-mounted, and so on. Moreover, such mounting may be static ordynamic, for example, in the latter case optionally involving additionalgimbal(s).

A gimbal ball and/or support can be used for any suitable function. Forexample, a gimbal ball can be used to point a payload of one or moredevices at a desired target or in a desired direction and/or to hold apayload in a substantially fixed orientation as the support to which thegimbal is mounted moves. Consistent with this flexibility, a gimbal ballcan include one or more still cameras, motion cameras, visible cameras,infrared cameras, and/or compasses, among others.

Some payload components occupy a relatively large volume. For example,camera lenses can be fairly large when designed to provide magnificationand/or work in low-light conditions. Such payload components,individually or collectively, can occupy all of the payload capacitythat a gimbal ball provides. Therefore, it is desirable to design gimbalballs with increased payload capacity, so that larger and/or morepayload components can be accommodated by a single gimbal ball.

Some payload components also can be relatively massive. As the mass of apayload increases, difficulties with moving and controlling the payloadcan arise. In particular, as explained below in more detail withreference to an illustrative embodiment, a gimbal ball can include twoor more constituent gimbals configured to rotate relative to oneanother. Such rotation can be effected by a motor configured to apply atorque to one or more of the gimbals. Accordingly, motors that canprovide improved (e.g., larger and/or more stable) torque can facilitatereliable aiming of the payload.

Some gimbal balls conform to industry standards that specify theexternal dimensions of the gimbal ball. For example, before approving agimbal ball, some regulatory agencies may rigorously test theaerodynamics, weight, and/or other attributes of the design, to helpensure that the ball does not unduly affect the performance of theassociated support (e.g., aircraft). In particular, the size, shape,weight, and/or other aspects of an outer expression of a gimbal ball maybe tested. Therefore, it is desirable to design gimbal balls withprofiles that previously have been approved and/or certified, thusobviating the need to undergo additional testing and/or certification.Furthermore, such gimbal ball designs may be off-the-shelf compatiblewith a variety of different supports that have been configured to workwith an industry-standard design.

Although regulatory considerations may constrain the outer expression ofa gimbal ball, and compatibility with various vehicles may constrain theconnection interface between the gimbal ball and the support, once aparticular design has been approved and/or certified, the inner workingsof a design can be customized without affecting the exterior expressionor interface compatibility. In particular, as described in detail below,a gimbal ball can be configured to enhance payload capacity and payloadcontrol without changing an outer expression of the gimbal ball.

The following examples further describe selected aspects and embodimentsof the present teachings. These aspects and embodiments includespace-saving features configured to accommodate one or more payloadcomponents, thus increasing the payload capacity of the gimbal ballwithout necessarily increasing the outer dimensions of the gimbal ball.These aspects and embodiments also include a motor configured to move atleast one gimbal relative to another gimbal about a first axis, with themotor peripherally mounted distal the axis. These examples and thevarious features and aspects thereof are included for illustration andare not intended to define or limit the entire scope of the disclosure.

EXAMPLE 1 Exemplary Gimbal Ball and Support System

This example describes an exemplary gimbal ball and support system.Specifically, FIG. 2 shows an exemplary gimbal ball 20 mounted on thebottom front of an exemplary support, helicopter 22. The exemplarygimbal ball can include cameras, such as visible and/or infraredcameras, and/or other sensing devices, for use in airborne surveying,reconnaissance, and/or targeting, among others. The gimbal ball also caninclude additional components, such as drivers and/or gyroscopes, amongothers, for effecting desired motions and/or resisting undesiredmotions, respectively.

EXAMPLE 2 Exemplary Gimbal Ball

This example describes an exemplary gimbal ball 20, including thelocation and interactions of various constituent gimbals; see FIG. 3.This exemplary gimbal ball could be used with a helicopter and/or otheraircraft, among others, for example, as shown in FIG. 2.

FIG. 3 shows exploded views of portions of gimbal ball 20. Inparticular, FIG. 3 shows a plurality of exemplary gimbals that cancooperate to support and point or otherwise orient a payload. The leftcolumn of FIG. 3 shows various gimbals associated with gimbal ball 20,including a minor-yaw gimbal 30, a minor-pitch gimbal 32, a major-pitchgimbal 34, and a major-yaw gimbal 36. Minor-pitch gimbal 32, inparticular, includes space-saving features configured to increasepayload capacity, as described below. The right column of FIG. 3 showsthe gimbals of the left column assembled together. In particular,assembly 40 includes minor-yaw gimbal 30 mounted within minor-pitchgimbal 32; assembly 42 includes assembly 40 mounted within major-pitchgimbal 34; and assembly 44 includes assembly 42 mounted within major-yawgimbal 36. Gimbal ball 20 also can include a payload, gyroscopes, cover,various motors, and/or control circuitry, among others. The gimbals havebeen illustrated here without such corresponding elements for simplicityand clarity.

Gimbal ball 20 is provided as a nonlimiting example of a gimbal ballthat can be used to point a payload of one or more devices at a desiredtarget or in a desired direction and/or to hold a payload in asubstantially fixed orientation, particularly as the support to whichthe gimbal is mounted moves. One or more gimbals of the ball, includingall gimbals of the ball, can be modified while remaining within thescope of this disclosure. Moreover, in some cases, one or more gimbalsof the ball can be moved (translationally and/or reorientationally),fixed, or removed.

In the illustrated embodiment, minor-yaw gimbal 30 provides a stage, orinner-mount, to which one or more devices may be mounted. For example, apayload including one or more cameras or other instruments can bemounted to gimbal 30. Exemplary gimbal 30 is provided as a nonlimitingexample of a mount to which payload components may be mounted. In someembodiments, such a gimbal may be configured differently so as toaccommodate different payloads. As described below, the various othergimbals can cooperate with gimbal 30 so that the payload can be pointedand/or maintained in a desired direction. To this end, the gimbals canbe configured to rotate relative to one another about two or moredifferent axes. Gimbal 30 is not necessarily the only gimbal to whichpayload components can be mounted. In some embodiments, one or morepayload components may be mounted on a subsequently described gimbal, orvariant thereof.

The components of gimbal ball 20 can be used to establish various levelsof rotation. For example, a first level of rotation can be establishedbetween gimbal 30 and gimbal 32. Gimbal 30 includes joints 50, andgimbal 32 includes complementary joints 52. Joints 50 and 52 can beconfigured complementarily for mutual engagement, so that gimbal 30 andgimbal 32 can rotate or pivot relative to one another about a yaw axisY. Arrow 54 shows the rotational direction of gimbal 30 with referenceto yaw axis Y. Such rotation may be referred to as yaw rotation and/orazimuthal rotation. In the illustrated embodiment, gimbal 30 is designedto provide minor (approximately ±4 degrees) rotation about the yaw axis;however, more generally, gimbal 30 may be used to provide any suitableor desired rotation (including a narrower or wider rotation range).Rotation of gimbal 30 can be used to make fine adjustments to theorientation of the payload, while larger adjustments and/or adjustmentsabout a different axis can be made by subsequently described componentsof the gimbal assembly.

A second level of rotation can be established between gimbal 32 andgimbal 34. Minor-pitch gimbal 32, also referred to as an inner elevationyoke, includes joints 56, and gimbal 34 includes complementary joints58. Joints 56 and 58 can be configured complementarily for mutualengagement, so that gimbal 32 and gimbal 34 can rotate or pivot relativeto one another about a pitch axis P. Arrow 60 shows the rotationaldirection of gimbal 32 with reference to pitch axis P. Such rotation maybe referred to as pitch rotation and/or elevational rotation. Suchrotation is translated to gimbal 30 so that a payload mounted to gimbal30 also rotates about the pitch axis. In the illustrated embodiment,pitch axis P is perpendicular to yaw axis Y by virtue of the relativepositioning of joints 52 and 56. As shown in FIG. 8, joints 52 and 56are not precisely coplanar. In some embodiments, a pitch axis and a yawaxis can be coplanar and/or in some embodiments a pitch axis and a yawaxis can be nonperpendicular. In the illustrated embodiment, gimbal 32is designed to provide minor (approximately ±4 degrees) rotation aboutthe pitch axis; however, more generally, gimbal 32 may be used toprovide any suitable or desired rotation (including a narrower or widerrotation range). Rotation of gimbal 32 can be used to make fineadjustments to the orientation of the payload, while larger adjustmentsand/or adjustments about a different axis can be made by subsequentlydescribed components of the gimbal ball.

A third level of rotation can be established between gimbal 34 andgimbal 36. Major-pitch gimbal 34 includes joints 62 and gimbal 36includes complementary joints 64. Joints 62 and 64 can becomplementarily configured for mutual engagement so that gimbal 34 andgimbal 36 can rotate relative to one another about pitch axis P′. In theillustrated embodiment, pitch axis P′ and pitch axis P are substantiallyequal (i.e., collinear). In other embodiments, for example, pitch axisP′ may be parallel to but offset from pitch axis P. Arrow 68 shows therotational direction of gimbal 34 with reference to pitch axis P′. Suchrotation is translated to gimbal 30, via gimbal 32, so that a payloadmounted to gimbal 30 also rotates about the pitch axis. In theillustrated embodiment, gimbal 34 is designed to provide major(approximately 38 degrees up and 238 degrees down) rotation about thepitch axis; however, more generally, gimbal 34 may be used to provideany suitable or desired rotation (including a narrower or wider rotationrange, in one or both directions). Rotation of gimbal 34 can be used tomake course adjustments to the orientation of the payload, while moreprecise adjustments can be made by rotation of gimbal 32 within gimbal34.

A fourth level of rotation can be established between gimbal 36 and asupport to which the gimbal is coupled, such as a helicopter or othervehicle. Major-yaw gimbal 36 includes a joint 66 configured to rotatablymount to a suitable support. Joint 66 can mount directly to a support ormount indirectly to a support via some intermediate structure. Arrow 69shows the rotational direction of gimbal 36 with reference to a yaw axisY′. Yaw axis Y′ may be skewed relative to yaw axis Y due to rotation ofone or more gimbals about a pitch axis. Rotation of gimbal 36 at joint66 is translated to gimbal 30, via gimbals 32 and 34, so that a payloadmounted to gimbal 30 also rotates about yaw axis Y′. In the illustratedembodiment, gimbal 36 is designed to provide major (continuous 360degree) rotation about yaw axis Y′; however, more generally, gimbal 36may be used to provide any suitable or desired rotation (including anarrower rotation range).

The above-described gimbal ball is provided as a nonlimiting example,and other gimbal balls are within in the scope of this disclosure. Inparticular, gimbal balls with more or fewer constituent gimbals, axes,levels of rotation, etc. can be used, establishing more or fewer levelsof rotation. Furthermore, each above-described gimbal is provided as anonlimiting example. Some gimbal balls may not include a gimbalcorresponding to one of the above-described gimbals, some gimbalassemblies may include additional gimbals not described above, and somegimbal assemblies may include modifications of the above-describedgimbals.

EXAMPLE 3 Exemplary Space-Saving Gimbals

This example describes exemplary space-saving gimbals, which may beconfigured to accommodate increased payload capacity and/or to provide alarger payload aperture, as mentioned above; see FIGS. 4-8.

FIGS. 4 and 5 somewhat schematically illustrate two differentminor-pitch gimbals, also referred to as inner elevation yokes. Inparticular, FIG. 4 shows a front view of a gimbal 70 with asubstantially continuous sidewall 72. Because sidewall 72 does notinclude a break, recess, and/or other space-saving feature, a payloadeffectively is laterally bound by the sidewall, as representedschematically at 74. In contrast, FIG. 5 shows a front view of gimbal32, which includes a sidewall 80 having space-saving features 82. Thesespace-saving features provide a passage through which a payload can atleast partially extend, as represented schematically at 84. In otherwords, if not for space-saving features 82, the payload could not extendlaterally past an inner surface of sidewall 80.

One or more of a variety of different space-saving features may be usedto improve payload capacity and/or to provide a larger payload aperture.For example, a gimbal sidewall may include one or more holes or slotsthrough which a payload may at least partially extend. In someembodiments, a gimbal sidewall can include a convexity that effectivelyincreases a volume internal the gimbal sidewall. In some embodiments, agimbal sidewall may include an open recess through which a payload mayat least partially extend. Such exemplary space-saving features, orvirtually any other feature that provides increased payload capacityand/or provides a larger payload aperture, can be incorporatedindividually or collectively into a particular gimbal design.

FIGS. 6 and 7 show axonometric views of gimbal 70 and gimbal 32,respectively. As shown in FIG. 6, gimbal 70 surrounds a payload 90. Asubstantially continuous sidewall 72 limits the lateral extent to whichthe payload can extend, thus effectively limiting the total payloadcapacity of the gimbal. As shown in FIG. 7, gimbal 32 holds a payload 92that occupies more volume and requires a larger aperture than payload90. Whereas payload 90 is laterally bound by sidewall 72, payload 92laterally extends through space-saving features 82 of sidewall 80, thusoccupying more space than payload 90. In other words, gimbal 32 canaccommodate a more voluminous payload than gimbal 70 because ofspace-saving features 82. Nonetheless, payload 92 and gimbal 32 do notcollectively occupy any more space than payload 90 and gimbal 70collectively occupy. As can be seen, improvements in payload capacitycan be achieved without negatively affecting the overall dimensions of agimbal assembly. Therefore, for example, either gimbal 70 and payload 90or gimbal 32 and payload 92 can be fit to operate within gimbal 34 ofFIG. 3.

FIG. 8 shows a side-view of minor pitch gimbal 32. Gimbal 32 includes aframe portion 100. Extending forward from the frame portion areprotrusions 102 where joints 52 are located and protrusions 104 wherejoints 56 are located. Protrusions 102 and protrusions 104 collectivelydefine space-saving features in the form of rearwardly extendingrecesses 82. Recesses 82 can accommodate one or more payload componentsthat extend into the space where the gimbal sidewall would be present ifnot for the recesses.

The useable space that recesses 82, and/or other space-saving features,provide can be appreciated by comparing gimbal 32 of FIGS. 7 and 8 withgimbal 70 of FIG. 6. As shown in FIG. 8, gimbal 32 includes a front edge106 that extends to an imaginary plane 110 near joints 52 and 56. Thefront edge diverges from this plane as it moves farther away from joints52 and 56, thus creating protrusions that define recesses 82. Recesses82 can be described as the gap between plane 110 and front edge 106.Such recesses can accommodate payload, thus increasing the payloadcapacity from that which could be contained laterally interior to thegimbal sidewall if the recesses were not present. In contrast, as can beseen in FIG. 6, a gimbal, such as gimbal 70, typically is configuredwith a front edge 76 that is substantially planar. Gimbal 70 does notinclude a recess or other space-saving feature that can accommodatepayload. Therefore, an assembly that utilizes a gimbal such as gimbal 70will not be able to accommodate as voluminous of a payload as can beaccommodated by a gimbal assembly that utilizes a gimbal such as gimbal32.

Recesses 82 of gimbal 32 are provided as a nonlimiting example of aspace-saving feature. More generally, gimbals may be designed withrecesses having different shapes and sizes, on a recess-by-recess basis.Furthermore, space-saving features other than recesses, such as holes,slots, convexities, etc., can be used instead of, or in addition to,recesses. In the illustrated embodiment, recesses 82 extend rearwardfrom imaginary plane 110 by at least 50% of the depth of gimbal 32.Other embodiments may have deeper or shallower recesses. In general,space-saving features can be sized to achieve a desired balance ofpayload capacity and structural integrity of the gimbal. In someembodiments, a recess of approximately 10%, 20%, 30%, or 40% may besuitable for accommodating smaller payload components. In otherembodiments, a recess of approximately 60%, 70%, 80%, or more may besuitable for accommodating larger payload components. Other space-savingfeatures can be designed to accommodate payload components at differentlocations of a gimbal. For example, payload components that occupysubstantial rearward space can be accommodated by holes near the rear ofthe gimbal. High-strength materials may be used to form or support agimbal that includes relatively large recesses or other space-savingfeatures.

EXAMPLE 4 Exemplary Driven Gimbals

This example describes exemplary mechanisms for driving a gimbal ball,or portions thereof; see FIGS. 9-12.

FIG. 9 schematically shows an exemplary gimbal assembly 118, inaccordance with aspects of the present teachings. Gimbal assembly 118includes four constituent gimbals 120, 122, 124, and 126, whichcorrespond to an inner-most layer, a second inner-most layer, a secondouter-most layer, and an outer-most layer. The inner layers are nearerthe middle of the gimbal assembly, while the outer layers are nearer theperiphery of the gimbal assembly. Gimbal assembly 118 also includes amotor 130 that has a first motor component 132 mounted to the inner-mostlayer, and a complementary second motor component 134 mounted to thesecond outer-most layer. As described above, the individual gimbals of agimbal assembly can be configured to move relative to one another aboutone or more axes. A motor, such as motor 130, can be used to effect suchmotion. In particular, the first motor component can apply a force tothe second motor component, and/or vice versa. The applied force betweenthe two components can cause the components to move relative to oneanother, thereby causing the gimbals to which the motor components aremounted to move relative to one another.

A motor can be configured to effect motion about a single axis, and twoor more motors can be configured cooperatively to effect motion abouttwo different axes, such as about perpendicular axes. When two or moremotors are used, one motor can be used to control pitch (rotation of onegimbal relative to another gimbal about a pitch axis), and another motorcan be used to control yaw (rotation of one gimbal relative to anothergimbal about a yaw axis). In some embodiments, a single motor can beconfigured to effect motion about two different axes.

The size and disposition of motors used in the gimbal assembly may beselected to increase payload size and driving efficacy. Relatively smallmotors and/or motors that can be placed at or near the periphery of agimbal assembly can improve useable payload capacity compared to largermotors and/or motors that are located closer to the center of a gimbalassembly where payload components are typically arranged. Furthermore,because torque is proportional to lever arm (torque (T)=lever arm(r)×force (F)), a motor can generate relatively more torque as thedistance between where the motor applies force and the axis about whichthe motor causes rotation increases. In other words, the farther themotor acts from an axis of rotation, the less force the motor will haveto generate to rotate one gimbal relative to another about that axis.

FIG. 10 shows aspects of an exemplary driver system, for example,suitable for the gimbal assembly of FIG. 3. FIG. 10 shows a front viewof gimbal 32 mounted to major pitch gimbal 34. FIG. 10 also shows ashell 140 connected to gimbal 34 and configured to partially encasegimbal 32 from behind. Shell 140 also can partially encase gimbal 30and/or associated payload when gimbal 30 and the payload are assembledas shown at 42 of FIG. 3. Shell 140, in particular, its inside surface,also provides a motor mounting location near the periphery of a gimbalassembly. FIG. 10 also shows a fine-pitch motor 142 that includes astator 144 mounted to gimbal 34 via shell 140. The fine-pitch motor alsoincludes a complementary rotor 146, drawn in dashed lines, that ismounted to gimbal 30 via a mounting assembly. FIG. 10 also shows afine-yaw motor 150 that includes a stator 152 mounted to gimbal 34 viashell 140. The fine-yaw motor also includes a complementary rotor 154,drawn in dashed lines, that is mounted to gimbal 30 via a mountingassembly. In the illustrated embodiment, fine-pitch motor 142 isconfigured to control relative movement between stator 144 and rotor 146about pitch axis P, and fine-yaw motor 150 is configured to controlrelative movement between stator 152 and rotor 154 about yaw axis Y. Inthis manner, motor 142 and motor 150 can cooperate to make fineadjustments to the pitch and yaw of a payload mounted to gimbal 30.

FIGS. 11 and 12 show a more detailed side-view of fine-pitch motor 142.Rotor 146 can move in an arc about a pitch axis. Although rotor 146moves in an arc as gimbal 30 rotates relative to gimbal 34 and shell140, a linear motor can be used to effect the motion. The gimbals can beconfigured to guide the rotor in an arc when a linear force is appliedbetween the stator and the rotor, thus allowing a linear motor to beused.

The driver(s) used in gimbal balls, as described herein, generallycomprise any mechanism for effecting a suitable or desired force (and/ortorque). Exemplary drivers may include linear motors, rotary motors,stepper motors, servo motors, brushed motors, brushless motors, DCmotors, AC motors, limited angle motors, and so on. These motors may bemixed or matched as desired or appropriate. A nonlimiting example of alinear motor is a linear electric motor, which utilizes magnetic forcesto effect movement between a rotor and a stator. A linear electric motoris essentially an electric motor that has been “unrolled” so thatinstead of producing a torque, it produces a linear force by setting upan electromagnetic field. Linear motors can be induction motors orstepper motors, among others. In the illustrated embodiment, stator 144includes a magnet, and rotor 146 includes a coil through which anelectric current can be directed, thus generating a magnetic field. Thecurrent can be controlled so as to generate a desired magnetic field,thus controlling the linear forces between the stator and the rotor.

In the illustrated embodiment, two motors are used to control fineadjustments. Motor 142 controls fine elevational adjustments, whilemotor 150 controls fine azimuthal adjustments. Both motors include acomponent mounted to an outer layer of the gimbal ball, namely gimbal 34via shell 140 and/or associated mounting structure. The shell extends tothe far periphery of the gimbal ball. Both motors also includecorresponding components mounted to an inner layer of the gimbal ball,namely gimbal 30. In some embodiments, motor components can be mountedto gimbal 30 via a mounting structure. One or more gimbals can beoperatively interposed between the gimbals that support the motorcomponents. For example, in FIG. 10, gimbal 32 is interposed betweengimbal 34 and gimbal 30. Rotors 146 and 154 extend through an opening160 of gimbal 32. In this manner, the motor can be spaced distal an axisabout which the motor is to cause rotation. The distance between such anaxis and the motor can be 70%, 80%, 90%, or even equal to or greaterthan 95% of the distance between the axis and the outer-most surface ofthe gimbal ball directly behind the motor.

Motor 142 is positioned proximate motor 150, as shown. Positioning themotors near each other obviates the need to design or maintain twoseparate locations for distally spaced motors. Adjacent motors canfacilitate a greater overall payload capacity than distally spacedmotors. Moreover, such proximate positioning also can allow power andcontrol wires to be run alongside one another and otherwise simplifyassembly and/or maintenance.

FIGS. 10-12 also show a rotational restrictor 170, including a fence 172and a peg 174 interior the fence. Rotational restrictor 170 effectivelylimits fine-rotation about the yaw and the pitch axis. The rotationalrestrictor can be designed so that, as the motors control fine movementbetween the gimbals, peg 174 moves within fence 172. However, the fenceprevents the peg from moving more than a predetermined distance in anydirection. The size and shape of fence 172 can be set to restrictivelyengage peg 174 when the payload has been rotated a predetermined amount.In the illustrated embodiment, the fence is generally circularly shaped,although this is not required. Fences having a circular shape can allowfor substantially equal-magnitude rotation in any direction. Conversely,fences having other shapes can be used to allow for different amounts ofrotation. For example, an oval fence can be used to allow greaterrotation about a pitch axis than about a yaw axis, or vice versa,depending on the orientation of the oval fence. Furthermore, in theillustrated embodiment, the fence is sized to allow approximately 4degrees of rotation in all directions. A larger fence can be used toallow more rotation, while a smaller fence can be used to allow lessrotation.

The disclosure set forth above may encompass multiple distinctinventions with independent utility. Although each of these inventionshas been disclosed in its preferred form(s), the specific embodimentsthereof as disclosed and illustrated herein are not to be considered ina limiting sense, because numerous variations are possible. The subjectmatter of the inventions includes all novel and nonobvious combinationsand subcombinations of the various elements, features, functions, and/orproperties disclosed herein. The following claims particularly point outcertain combinations and subcombinations regarded as novel andnonobvious. Inventions embodied in other combinations andsubcombinations of features, functions, elements, and/or properties maybe claimed in applications claiming priority from this or a relatedapplication. Such claims, whether directed to a different invention orto the same invention, and whether broader, narrower, equal, ordifferent in scope to the original claims, also are regarded as includedwithin the subject matter of the inventions of the present disclosure.

1. A gimbal, comprising: a frame portion; a first protrusion extendingfrom the frame portion; a first joint located at the first protrusionand configured to permit an inner mount supporting a payload componentto selectively rotate about a first axis passing through the firstprotrusion; a second protrusion extending from the frame portion; and asecond joint located at the second protrusion and configured to permitthe gimbal to selectively rotate about a second axis passing through thesecond protrusion, wherein the first protrusion and the secondprotrusion collectively define a recess at the periphery of the gimbalconfigured to accommodate at least a portion of the payload component.2. The gimbal of claim 1, further comprising a third protrusionextending from the frame portion opposite the first protrusion, andfurther comprising a third joint located at the third protrusion andconfigured to cooperate with the first joint to permit the inner mountto selectively rotate about the first axis.
 3. The gimbal of claim 2,wherein the second protrusion and the third protrusion collectivelydefine a recess configured to accommodate at least a portion of apayload component supported by the inner mount.
 4. The gimbal of claim1, further comprising a fourth protrusion extending from the frameportion opposite the second protrusion, and further comprising a fourthjoint located at the fourth protrusion and configured to cooperate withthe second joint to permit the gimbal to selectively rotate about thesecond axis.
 5. The gimbal of claim 4, wherein the first protrusion andthe fourth protrusion collectively define a recess configured toaccommodate at least a portion of a payload component supported by theinner mount.
 6. The gimbal of claim 1, wherein the first axis isperpendicular to the second axis.
 7. The gimbal of claim 1, wherein therecess extends at least 20% of a distance from a front edge of thegimbal toward a back of the gimbal.
 8. The gimbal of claim 1, whereinthe recess extends at least 40% of a distance from a front edge of thegimbal toward a back of the gimbal.
 9. The gimbal of claim 1, whereinthe recess extends at least 50% of a distance from a front edge of thegimbal toward a back of the gimbal.
 10. The gimbal of claim 1, whereinthe recess is one of a plurality of recesses, each configured toaccommodate at least a portion of a payload component.
 11. The gimbal ofclaim 1, wherein the shortest path between the first and secondprotrusions that lies completely within the frame is at least abouttwice as long as the shortest distance between the first and secondprotrusions.
 12. A gimbal ball, comprising: an inner mount configured tosupport a payload component; an outer carriage including first andsecond protrusions collectively defining a recess at the periphery ofthe outer carriage configured to accommodate at least a portion of thepayload component; and a gimbal joint rotatably connecting the innermount to the first protrusion of the outer carriage.
 13. The gimbal ballof claim 12, further comprising a payload component supported by theinner mount and at least partially occupying the recess.
 14. The gimbalball of claim 13, wherein the payload component includes an instrumentfor measuring radiation.
 15. The gimbal ball of claim 12, furthercomprising a second gimbal joint rotatably connecting the outer carriageto a support gimbal.
 16. The gimbal ball of claim 15, wherein the firstgimbal joint is configured to permit rotation about a first axis and thesecond gimbal joint is configured to permit rotation about a secondaxis, different than the first axis.
 17. The gimbal ball of claim 16,wherein the first axis is perpendicular to the second axis.
 18. A gimbalball, comprising: inner gimbal means for supporting a payload component;outer gimbal means including space-saving means for accommodating thepayload component; and joint means for rotatably connecting the innergimbal means to the outer gimbal means.